首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   40006篇
  免费   3488篇
  国内免费   1521篇
  2023年   399篇
  2022年   865篇
  2021年   1520篇
  2020年   909篇
  2019年   1208篇
  2018年   1188篇
  2017年   866篇
  2016年   1326篇
  2015年   2019篇
  2014年   2311篇
  2013年   2689篇
  2012年   3301篇
  2011年   3004篇
  2010年   1894篇
  2009年   1667篇
  2008年   2086篇
  2007年   1976篇
  2006年   1745篇
  2005年   1712篇
  2004年   1548篇
  2003年   1426篇
  2002年   1395篇
  2001年   498篇
  2000年   442篇
  1999年   556篇
  1998年   464篇
  1997年   377篇
  1996年   353篇
  1995年   307篇
  1994年   283篇
  1993年   265篇
  1992年   294篇
  1991年   257篇
  1990年   232篇
  1989年   236篇
  1988年   204篇
  1987年   161篇
  1986年   150篇
  1985年   185篇
  1984年   160篇
  1983年   161篇
  1982年   197篇
  1981年   198篇
  1980年   145篇
  1979年   119篇
  1978年   136篇
  1977年   105篇
  1976年   105篇
  1975年   90篇
  1974年   98篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Excessive pulmonary inflammatory response is critical in the development of acute lung injury (ALI). Previously, microRNAs (miRNAs) have been recognized as an important regulator of inflammation in various diseases. However, the effects and mechanisms of miRNAs on inflammatory response in ALI remain unclear. Herein, we tried to screen miRNAs in the processes of ALI and elucidate the potential mechanism. Using a microarray assay, microRNA let-7e (let-7e) was chose as our target for its reported suppressive roles in several inflammatory diseases. Down-regulation of let-7e by antagomiR-let-7e injection attenuated LPS-induced acute lung injury. We also found that antagomiR-let-7e could obviously improve the survival rate in ALI mice. Moreover, antagomiR-let-7e treatment reduced the production of proinflammatory cytokines (i.e., TNF-α, IL-1β and IL-6) in bronchoalveolar lavage fluid (BALF) of LPS-induced ALI mice. Luciferase reporter assays confirmed that suppressor of cytokine signaling 1 (SOCS1), a powerful attenuator of nuclear factor kappa B (NF-κB) signaling pathway, was directly targeted and suppressed by let-7e in RAW264.7 cells. In addition, it was further observed that SOCS1 was down-regulated, and inversely correlated with let-7e expression levels in lung tissues of ALI mice. Finally, down-regulation of let-7e suppressed the activation of NF-κB pathway, as evidenced by the reduction of p-IκBα, and nuclear p-p65 expressions in ALI mice. Collectively, our findings indicate that let-7e antagomir protects mice against LPS-induced lung injury via repressing the pulmonary inflammation though regulation of SOCS1/NF-κB pathway, and let-7e may act as a potential therapeutic target for ALI.  相似文献   
952.
Lang  Hong  He  Yuting  Li  Fengcheng  Ma  Dianrong  Sun  Jian 《Plant Growth Regulation》2021,94(3):261-273
Plant Growth Regulation - Weedy rice is one of the most severe weeds in paddy fields, characterized by its high degree of seed shattering. Abscisic acid (ABA) serves as an abscission-accelerating...  相似文献   
953.
954.
Zhang  Zekun  Su  Rui  Chang  Chao  Cheng  Xiao  Peng  Qi  Lambers  Hans  He  Honghua 《Plant and Soil》2021,461(1-2):501-515
Plant and Soil - Residues of antibiotics such as oxytetracycline (OTC) in soil can affect microbial compositions and activities, thus affecting soil P availability, and consequently plant P uptake...  相似文献   
955.
956.
957.
958.
959.
960.
Length-to-weight and length-to-length ratios were estimated for six cavefishes including Yunnanilus longibarbatus, Yunnanilus bailianensis, Yunnanilus jinxiensis, Oreonectes polystigmus, Paranemachilus pingguoensis, and Paranemachilus genilepis from the upper reaches of the Pearl River, Guangxi Province, China (between 106.26E, 23.14N and 111.42E, 24.85N). The fish were captured between May and October in 2018 and 2019 using trap nets (mesh size 7 mm) set in front of selected caves at 6:30–7:30 p.m. and were hauled out at 6:30–7:30 a.m. the next day. After removal, the fish were measured and weighed immediately to the nearest 0.1 cm and 0.1 g, respectively. The regression parameter r2 was between .95 and .98. The total length-to-standard length ratios were also calculated with r2 ≥ .98. This study should provide a useful reference for biological studies and biodiversity conservation of cavefish.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号